feat(themes): warn about animated themes on high-CPU setups (#1020)

* feat(themes): warn about animated themes on high-CPU setups

Show a warning icon + tooltip on animated themes (those defining
@keyframes) in the store and in Your Themes, on Linux setups where
animation is costly — the Nvidia WebKit quirk is active or compositing
is forced off. The Nvidia detection already runs once at startup; its
result is recorded (theme_animation.rs) and read via a new
theme_animation_risk command — no GPU re-probe. Display-only; never
shown off Linux. The animated flag comes from the registry (store) or
the theme CSS (Your Themes).

* docs(themes): note the animated-theme warning PR in the Theme Store entry

src/locales/ru/settings.ts

@@ -402,6 +402,7 @@ export const settings = {
   tabThemes: 'Темы',
   themesYourThemesTitle: 'Ваши темы',
   themesCvdTooltip: 'Безопасно при дальтонизме — дейтеранопия, протанопия, тританопия',
+  themeAnimationWarning: 'Эта тема использует анимации, которые могут повысить нагрузку на процессор в вашей конфигурации (Nvidia/Linux или композитинг выключен).',
   themeStoreTitle: 'Магазин тем',
   themeStoreSubmitText: 'Создали свою тему? Поделитесь с сообществом — подробности в репозитории тем.',
   themeStoreSubmitLink: 'Открыть репозиторий тем',